Polyamide resins have good fabricability, mechanical properties and chemical resistance and thus have been widely used as various part materials for garments, industrial materials, automobile, electric and electronic, industrial products, and the like.
Recently, molded articles using a polyamide resin have sometimes been molded under high cycle molding conditions at a high molding temperature and a reduced mold temperature to enhance the productivity.
Also, polyamide resins are widely used in the automobile field, and for such applications, the usage environment is thermally and mechanically rigorous, and currently many cases often require both impact properties and surface appearance properties to automobile exterior parts, in particular, represented by fender mirrors.
On the other hand, when the molding is carried out under a high temperature condition, failure to provide a molded article stably sometimes occurs as a problem because of the degradation of polyamide resins and the occurrence of change in the fluidity.
For this reason, there is a demand for a polyamide resin which has improved surface appearance stability of a molded product and even impact resistance properties when subjected to the high cycle molding as described above and causes little physical property changes under intense molding conditions.
To meet such a demand, a polyamide composed of Polyamide 66/6I to which an isophthalic acid component is introduced is disclosed as a material capable of enhancing the surface appearance and mechanical properties of a molded product (see, for example, Patent Documents 1 to 4). Also, a polyamide composed of Polyamide 6T/6I to which a terephthalic acid component and an isophthalic acid component are introduced is disclosed as a material capable of improving impact resistance properties (see, for example, Patent Document 5).